1. Field of the Invention
This invention relates to computer systems and, more particularly, to apparatus for cooling very high density systems of hybrid electronic circuits used in computer systems.
2. History of the Prior Art
The semiconductor and other devices utilized in modern computer systems function correctly only when operating within specified temperature ranges. In general, the components are designed to operate reliably within a relatively narrow range which may extend to about 100 degrees C. at the upper limit. Above this point, the devices themselves are unreliable in handling digital information and may well be destroyed as the temperature rises. Typically desktop computer systems such as personal computers and work stations include a motherboard upon which are positioned a central processing unit, memory, and input/output circuitry connected to a system bus. Slot connections are provided to the system bus on the motherboard for system peripheral components. Ambient air driven often driven by small fans installed within the cases of the computers cool the electronic circuitry to appropriate operating temperatures.
An entirely different packaging arrangement which is the subject of copending patent application Ser. No. 07/553,521, entitled Three Dimensional Packaging Arrangement for Computer Systems and the Like, filed July 13, 1989, on even date herewith, H. Davidson, allows an entire computer with 0.5 gigabytes of random access storage and as many as four individual processors to be contained in a volume approximately four inches on a side and one inch thick. Such a compact arrangement is obtained by allowing very thin layers of hybrid circuits to be essentially placed against one another to form a total computer package. Such a powerful computer is capable of operating at faster speeds than are conventionally packaged computers because of the short lengths of the conductors used. However, the higher packing densities have tended to raise the temperature to a level which normal cooling devices cannot handle.
In order to obtain very fast operating speeds from such a computer, very high speed devices may be used in the embedded chips. These devices require a great deal of power and operate to produce very high temperatures. With such a system, as much as two hundred amps of current may be utilized at each layer, producing as much as 1000 watts of power at each of a number of the layers of the arrangement. Prior art cooling techniques will simply not keep a computer of this sort within the operating temperature limits of its electronic devices, and the apparatus will destroy itself within a very short time after power is applied.